Field of the Invention
The present invention relates to an image processing apparatus which performs image processing for blurring an undesired part of an image, an imaging apparatus including the image processing apparatus, and an image processing method for performing blurring of an undesired part of an image.
Description of the Related Art
One of camera photographing techniques has been known for intentionally blurring a part excluding a subject to maximize the distinction between the part and the subject. However, because a compact digital camera has a small image pickup device, for example, a shallow depth of field may not be achieved, and therefore a sufficient blur may not be expressed. Accordingly, a technology has been proposed for adding a blur to a captured image by performing image processing. Japanese Patent Application Laid-Open No. 2005-025766 discloses a technology which uses a captured image and a distance information image to perform blurring processing including performing a convolution calculation for each distance range in order of a background and a foreground, for example, and thus generate a blurred image.
In order to perform highly accurate blurring processing on a foreground and a background, as in Japanese Patent Application Laid-Open No. 2005-025766, luminance information of a background (occlusion region) hided by a foreground must be considered. However, Japanese Patent Application Laid-Open No. 2005-025766 performs blurring processing without considering such luminance information. As a result, an image having undergone blurring processing is likely to include artifacts.